In a statement, the UN agency said that minors frequently suffer from lack of protection, medical care, quality education and proper nutrition.
According to UNICEF, 393 million of these children live in sub-Saharan Africa, while 64 million subsist in the Middle East.
Syria, Nigeria, Afghanistan, Yemen, South Sudan and Haiti are among the countries where the greatest number of children suffer the consequences of wars and natural disasters.
Despite significant progress, too many minors continue to be affected by crises, poverty and discrimination on grounds of religion, gender, race, ethnicity and disability.
Executive director of the agency, Anthony Lake, drew attention to the fact that more than 500 million children suffer such an adverse situation, "a figure that demonstrates the importance of our work."
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